class_docstr: Describes how to name items that are involved in a MetricFlow query.
  
  Most useful for group-by-items as there are different ways to name them like "user__country"
  or "TimeDimension('metric_time', 'DAY')".
docstr: Given an input that follows this scheme, return a spec pattern that matches the described input.
  
  If the input_str does not follow this scheme, raise a ValueError. In practice, input_str_follows_scheme() should
  be called on the input_str beforehand.
docstr_tok: ["Given","an","input","that","follows","this","scheme",",","return","a","spec","pattern","that","matches","the","described","input",".","If","the","input_str","does","not","follow","this","scheme",",","raise","a","ValueError",".","In","practice",",","input_str_follows_scheme","(",")","should","be","called","on","the","input_str","beforehand","."]
code: def spec_pattern(self, input_str: str) -> SpecPattern:
      """Given an input that follows this scheme, return a spec pattern that matches the described input.
  
      If the input_str does not follow this scheme, raise a ValueError. In practice, input_str_follows_scheme() should
      be called on the input_str beforehand.
      """
      pass
  
file_path: metricflow/metricflow/naming/naming_scheme.py
imports: from __future__ import annotations
  from abc import ABC, abstractmethod
  from typing import Optional
  from metricflow.specs.patterns.spec_pattern import SpecPattern
  from metricflow.specs.specs import InstanceSpec
label_desc: Use image node_id 2 for calling the QueryItemNamingScheme obj's underlying member method code with example usage: obj.spec_pattern(input_str) without return types